6746 results about "Nanofiltration" patented technology

A composite membrane and method for making the same, comprising a porous support and a polyamide surface. The subject membrane provides improved flux and/or rejection rates. The subject membrane is further capable of operating at lower operating pressures. The subject method includes reacting a polyfunctional amine with a polyfunctional acyl halide to form a polyamide. The method includes the step of contacting a complexing agent with the polyfunctional acyl halide prior substantial reaction between the polyfunctional acyl halide and a polyfunctional amine. The subject process is easily adapted to commercial scale manufacturing processes and is particularly suited for making nanofiltration and reverse osmosis composite membranes.

A desalination process is disclosed which combining two or more substantially different water treatment processes in a unique manner to desalinate saline water, especially sea water, to produce a high yield of high quality fresh water, including potable water, at an energy consumption equivalent to or less than much less efficient prior art desalination processes. In this process a nanofiltration step is synergistically combined with at least one of sea water reverse osmosis, multistage flash distillation. multieffect distillation of vapor compression distillation to provide an integrated desalination system by which sea water can be efficiently and economically converted to high quality potable water in yields which are at least 70%-80% greater than the yields available from the prior art processes. Typically a process of this invention using the nanofiltration initial step will produce, with respect to sea water feed properties, calcium, magnesium, sulfate and bicarbonate ion content reductions of 63%-94%, pH decreases of about 0.4-0.5 units and total dissolved solids content reductions of 35%-50%.

A cross flow filtration apparatus for nanofiltration or reverse osmosis has pressure vessels with a plurality of filter cartridges in each vessel. A feed port is provided at an intermediate position on the side of the vessel, and two permeate flows or branches exit opposite ends of the vessel, and the first branch has a characteristically high “upstream” flux and quality, while the second is of lesser flux and/or quality. The system provides a high degree of moduarity, enhancing flux or yield at a reduced driving pressure or overall pressure drop. Centered or off-center port, and a stop or valve in the permeate stream may apportion flows between the two outlets. Staged systems may employ a first stage bypass to achieve a target quality with increased yield. A flow divider or adaptor permits the cartridges to fit and seal in the vessel and an installation tool or sleeve may facilitate installation or replacement of cartridges having a directional perimeter seal. A tool permits modules to be bi-directional installed in the pressure vessel. Other embodiments involve adapting a conventional vessel designed for end-to-end feed flow utilizing a restrictor, obstruction or valve inside the filter cartridge to bifurcate or otherwise split or apportion the permeate. RO elements may be modified to movably position an obstruction or valve along a string of the elements and vary the take-off to two or more permeate outlets, or to provide pressure relief valves that present different pressure conditions for different elements of a string. A pressure vessel may have an intermediate inlet, with symmetric or asymmetric branching of permeate flow to opposed ends of the vessel, enhancing permeate flux, permeate quality and/or energy efficiency.

A mobile station and methods are disclosed for diagnosing and modeling site specific effluent treatment facility requirements to arrive at a treatment regimen and/or proposed commercial plant model idealized for the particular water/site requirements. The station includes a mobile platform having power intake, effluent intake and fluid outflow facilities and first and second suites of selectably actuatable effluent pre-treatment apparatus. An effluent polishing treatment array is housed at the station and includes at least one of nanofiltration, reverse osmosis and ion-exchange stages. A suite of selectively actuatable post-treatment apparatus is housed at the station. Controls are connected at the station for process control, monitoring and data accumulation. A plurality of improved water treatment technologies is also disclosed. The modeling methods include steps for analyzing raw effluent to be treated, providing a field of raw effluent condition entry values and a field of treated effluent condition goals entry values, and utilizing said fields to determine an initial treatment model including a selection of, and use parameters for, treatment technologies from the plurality of down-scaled treatment technologies at the facility, the model dynamically and continuously modifiable during treatment modeling.

Sodium chloride and purified water are recovered by treating salt water that contains sodium chloride with an integrated reverse osmosis and electrodialysis system, which includes an efficiency-enhancing feature that is one or more of the following: the use of univalent anion and univalent cation selective membranes in the electrodialysis unit; the addition of a nanofiltration unit to process the diluate from the electrodialysis unit; or operation of the electrodialysis unit at an elevated pressure. Magnesium and bromine can optionally be produced when the salt water contains these materials.

Water treatment systems and methods. Embodiments provide water treatment systems which comprise first oxidation, particulate filtration, and membrane filtration subsystems in that order. Systems also comprise recirculation paths and sensors for these subsystems. A controller determines whether to recirculate water to a previous subsystem in the order. Systems can comprise downstream second oxidation, high pressure membrane, ion exchange, activated carbon subsystems and/or ultraviolet contactors. Systems with high pressure membranes can comprise a pump before the high pressure membranes, a booster pump of the high pressure membrane subsystem, and a damping tank. In such systems the controller maintains a pressure in the damping tank. High pressure membrane subsystems can further comprise nanofiltration membranes and RO membranes. Systems can comprise bypass paths for some/all of the subsystems. For such systems, the controller further determines, whether to bypass these subsystems.

A mobile station and methods are disclosed for diagnosing and modeling site specific effluent treatment facility requirements to arrive at a treatment regimen and/or proposed commercial plant model idealized for the particular water/site requirements. The station includes a mobile platform having power intake, effluent intake and fluid outflow facilities and first and second suites of selectably actuatable effluent pre-treatment apparatus. An effluent polishing treatment array is housed at the station and includes at least one of nanofiltration, reverse osmosis and ion-exchange stages. A suite of selectively actuatable post-treatment apparatus are housed at the station. Controls are connected at the station for process control, monitoring and data accumulation. A plurality of improved water treatment technologies are also disclosed.

The invention discloses a desulfurization waste water zero discharging process. The process comprises a chemical dosing softening process and a microfiltration membrane treatment process; after incoming water is subjected to two-stage softening, nanofiltration and reverse osmosis separation are performed; sodium sulfate decahydrate with the purity of more than 99% is separated out by utilizing freezing crystallization; a reverse osmosis concentrated water regeneration sodium ion exchange device is utilized; sodium chloride with the purity of more than 98% is separated out by utilizing evaporative crystallization; solids are comprehensively utilized, and no liquid is discharged outside. The invention further provides a desulfurization waste water zero discharging system. According to the desulfurization waste water zero discharging process and the system, water in desulfurization waste water can be separated to be reutilized as domestic and industrial usable water, and other impurities in the desulfurization waste water are separated in solid form, so that pollutants harmful to the natural environment do not generate, and the problem that the desulfurization waste water pollutes the environment can be completely solved.

The present invention pertains to an apparatus and method for treating a solution of high osmotic strength, especially seawater and solutions of greater than 20 bar osmotic pressure, by passing the solution through a vessel containing spiral wound reverse osmosis or nanofiltration elements. The vessel contains at least three elements in series and at least two of these elements have standard specific fluxed that differ by at least 50%. The invention allows a more even flux distribution within a filtration system to be obtained, and it may advantageously be combined with variations en element construction and feed spacers.

A process for manufacturing xylose by extracting hemicellulose from a cellulosic material, such as by a cold caustic extraction method, concentrating the extract, such as by nanofiltration, into a hemicaustic stream containing hemicellulose with greater than about 85 wt % xylan content, and subsequently hydrolysing the xylan from the hemicaustic stream to xylose. The high concentration of xylan within the concentrated hemicaustic stream enables hydrolyzation of the xylan to food-grade xylose and, optionally, hydrogenation of the xylose to xylitol without the need of a chromatographic separation step as previously required.

An integrated treatment system using electrodialysis and pressure-driven membranes for deionizing and decontaminating liquids to a near-pure quality for use or reuse in industrial or municipal operations. The integrated system includes steps of pre-filtering contaminated feed liquids blending the filtered liquids in preparation for treating the mixed liquids in parallel or sequential treatment steps utilizing nanofiltration or reverse osmosis, proceeded by or followed by an integrated electrodialysis treatment. A control means selectively directs mixed liquids to each of the treatment units for treatment in parallel or in series depending on the conductivity and residual contaminants in the mixed liquids. In comparison with nanofiltration or reverse osmosis only systems, or electrodialysis only systems, the integrated system provides improved efficiencies for treatment, requires less energy to operate, and reduces maintenance and capital costs.

The nanofiltration process is suitable for Mg-Li separation and Li enriching of Li containing bittern or Li containing solution from salt lake to prepare lithium carbonate or lithium chloride with the Li enriching bittern. Nanofiltration membrane is used in separating and enriching lithium from lithium containing bittern, which contains Mg, Ca and other cations and sulfate radical and other anions and has Li ion concentration of 0.1-11.5 g/L and Mg/Li ion weight ratio 1-200, to obtain lithium enriched bittern suitable for preparing lithium carbonate or lithium chloride. The said process is effective, and can obtain lithium enriched bittern with Mg/Li ion weight ratio 0.6-5 and Li ion content of 0.6-20 g/L.

A membrane is provided including a coating layer having cellulose nanofibers produced from oxidized cellulose microfibers and an electrospun substrate upon which the coating layer is applied. The nanofibers of the electrospun substrate have a diameter greater than that of the cellulose nanofibers. The membrane also has non-woven support upon which the electrospun substrate is disposed. Microfibers of the non-woven support have a diameter greater than that of the nanofibers of the electrospun substrate. Application of electrospun membrane is in microfiltration area, while the cellulose nanofiber membrane serves in ultra-filtration, nanofiltration, and reverse osmosis after chemical modification.

A desalination plant for treating a sea water or brackish water feed is provided. The desalination plant includes a first treatment section to effectively remove scaling species, the first treatment section including nanofiltration section, the nanofiltration section including at least two stages and at least two passes; and a reverse osmosis section that operates at high recovery to produce a purified permeate stream and a selectively NaCl salt-enriched reject stream as a saline output.

The invention relates to a hyperfiltration membrane or nanofiltration membrane with a multi-layered composite structure and a preparation method thereof. The hyperfiltration membrane or nanofiltration membrane is a polymer electrostatic spinning nanofiber membrane layer characterized in strong chemical resistance prepared through an electrostatic spinning method, a hydrophilic polymer ultra-thin separation layer obtained through interfacial polymerization, and a functional group surface modification functional layer formed through the grafting reaction of reactant gases on the surfaces of hydrophilic polymers, or a long-chain polymer surface modification functional layer formed through the grafting reaction of the reaction gases on the surfaces of the hydrophilic polymers, or a functionalgroup-containing long-chain polymer surface modification functional layer through the grafting reaction of the reaction gases with the functional groups on the surfaces of the hydrophilic polymers. The hyperfiltration membrane or nanofiltration membrane with the multi-layered composite structure has the advantages of high water flux, high cutting rate and stable chemical performances. The filtration membrane can be used for the production of domestic water, drinking water or water in special conditions, and is suitable for the medical field, food field, environmental protection field and the like.

The present invention relates to a composite membrane for gas separation and/or nanofiltration of a feed stream solution comprising a solvent and dissolved solutes and showing preferential rejection of the solutes. The composite membrane comprises a separating layer with intrinsic microporosity. The separating layer is suitably formed by interfacial polymerisation on a support membrane. Suitably, at least one of the monomers used in the interfacial polymerisation reaction should possess concavity, resulting in a network polymer with interconnected nanopores and a membrane with enhanced permeability. The support membrane may be optionally impregnated with a conditioning agent and may be optionally stable in organic solvents, particularly in polar aprotic solvents. The top layer of the composite membrane is optionally capped with functional groups to change the surface chemistry. The composite membrane may be cured in the oven to enhance rejection. Finally, the composite membrane may be treated with an activating solvent prior to nanofiltration.

The invention discloses a high-selectivity composite nanofiltration membrane and a preparation method thereof. The high-selectivity composite nanofiltration membrane comprises a nonwoven layer and a polymer porous supporting layer; and the porous supporting layer is provided with one or two polyamide surface layers prepared by reacting polyamine and/or amine polyalcohol with chlorine polyacyl. Compared with the prior art, by forming one or two polyamide surface layers on the porous supporting layer through an interfacial polymerization method, the nanofiltration membrane has increased thickness of a surface layer, has more smooth, hydrolysis-resistant, oxidation-resistant and scratch-resistant surface, and improves pollution resistance; and the surface of the membrane can carry negative or positive charges, so that the composite nanofiltration membrane has a high-selectively functional desalting layer; besides, the method for preparing the composite nanofiltration membrane is simple to operate, high water flux and desalination rate are ensured under low pressure, and the service life of the membrane component is prolonged.

The invention discloses an advanced treatment system and method for high-concentration percolate in a comprehensive garbage disposal plant, belonging to the field of industrial waste water treatment. The system is formed by connecting a regulating tank, a coagulative precipitation tank, an upflow anaerobic sludge bed reaction tank, a primary anoxic and aerobic membrane bioreactor, advanced oxidation treatment equipment, a secondary anoxic and aerobic membrane bioreactor, nanofiltration membrane treatment equipment, an ozone contact tank and an active carbon filtering tower in sequence. According to the system, garbage percolate can be treated comprehensively, different pollutants in garbage percolate are treated in a classified way by combining physical, chemical and biological treatment,advanced treatment of garbage percolate is realized, and classified treatment for removing pollutants such as organic matters, heavy metals, ammonia, nitrogen and the like is performed, so that treated effluent strictly reaches the requirement of water pollution discharge degree limit in the Household Garbage Landfill Pollution Control Standard, the system runs stably for a long time, and treatment cost is lower than that of a secondary disc pipe reverse osmosis membrane process.

The invention discloses a zero-emission integrated process for treatment and reuse of high-salinity wastewater. The invention relates to a softening desalination treatment technology of water and particularly relates to a reuse treatment system for reverse osmosis concentrated water containing low-concentration organic matters which can achieve the requirement of 'zero emission'. The integrated process comprises the following steps: (1) firstly softening and pre-treating the high-salinity wastewater; (2) acquiring pre-treated water by virtue of activated carbon adsorption and an ultrafiltration device; (3) acquiring nanofiltration softened water and nanofiltration concentrated water by virtue of a nanofiltration device; (4) acquiring reverse osmosis softened water and reverse osmosis concentrated water by virtue of a reverse osmosis device; (5) acquiring electrodialysis softened water and electrodialysis concentrated water by virtue of an electrodialysis device; and (6) carrying out evaporation crystallization treatment on the electrodialysis concentrated water by virtue of an evaporation-crystallization device, regularly outwards transporting salts generated by the evaporation crystallization, feeding generated salt into a water-producing tank to enter a reuse system and finally completing the treatment and reuse of high-salinity wastewater. The integrated process is mainly used for the integrated treatment of the high-salinity wastewater.

The invention provides a treating method for sewage containing sodium sulfate and sodium chloride. The method comprises a step of preparing sewage to be treated as raw water and a step of carrying out nanofiltration on the raw water. The method may also comprise a step of carrying out evaporative crystallization on concentrated water obtained after nanofiltration so as to obtain anhydrous sodium sulfate. The method may further comprise a step of carrying out reverse osmosis treatment on yielded water obtained after nanofiltration and using yielded water obtained after reverse osmosis treatment as diluting water in nanofiltration of the raw water. The method may also comprise a step of carrying out secondary nanofiltration on yielded water obtained after nanofiltration so as to obtain concentrated water and yielded water obtained after secondary nanofiltration, a step of carrying out reverse osmosis treatment on yielded water obtained after secondary nanofiltration and carrying out evaporative crystallization on concentrated water obtained after reverse osmosis treatment so as to obtain sodium chloride, a step of using yielded water obtained after reverse osmosis treatment as diluting water in nanofiltration of the raw water, and a step of carrying out evaporative crystallization on concentrated water obtained after secondary nanofiltration in the sequence of concentration so as to obtain anhydrous sodium sulfate or subjecting the concentrated water together with next batch of raw water to nanofiltration again . The method provided in the invention can be used for separating and purifying anhydrous sodium sulfate and sodium chloride and for purifying sewage.

The invention provides a processing method for reducing and recycling organic waste water. The method comprises steps: (1) pre-treating waste water to obtain pre-treated out-water; (2) treating the out-water obtained from the step (1) through solid-liquid separation; (3) nano-filtering the out-water obtained from step (2); (4) treating nano-filtered concentrated water obtained from the step (3) to obtain out-water subjected concentrated water nano-filtering, returning to the step (3) for mixing the out-water subjected to concentrated water nano-filtering with the out-water subjected to solid-liquid separation, and performing nano-filtering; (5) performing first reverse osmosis treatment on out-water obtained from the step (3) through nano-filtering; (6) performing second reverse osmosis treatment on concentrated water obtained from the step (5) through first reverse osmosis treatment; and (7) evaporating and crystallizing a concentrated liquid obtained from the step (6) through second reverse osmosis treatment in order to obtain crystallized salt and evaporated concentrated water. The invention further provides a processing system of the method. Through the method and system, waste water is truly reduced and recycled.

The invention discloses a crosslinking hyper branched polymer composite nanofiltration membrane as well as the preparation method thereof. The crosslinking hyper branched polymer composite nanofiltration membrane is prepared by taking an ultrafiltration membrane as a basement membrane and crosslinking hyper branched polymer as a selecting layer through hyper branched polymer and the interfacial polymerization of polybasic acid, polybasic acyl chloride, polybasic anhydride and polybasic amine; and the interfacial polymerization takes the mixed solution of water and ethanol as the water phase and n-hexane, n-heptane or n-octane as the organic phase. As the hyper branched polymer has the spheroidal structure, a plurality of nano-voids exist in the interior of the molecule, so as to enable the selecting layer of the crosslinking hyper branched polymer composite nanofiltration membrane to be looser, and leads the nanofiltration membrane to maintain high flux and retention rate under the lower operating pressure. The nanofiltration membrane can be used in the fields of medicament, foodstuff, environmental protection, etc. The composite nanofiltration membrane is applicable to the separation and the condensation of high valence ions, low valence ions, neutral particles, drugs, food additives, etc.